Welcome to the Revolution

Hi there, welcome to my blog - La Revolution Deux. It's an odd name - but I like it! Here you will find all the info on my various DIY Guitar effects builds, amplifiers and guitars. Everything from a humble Ibanez tubescreamer to the holiest KLON Overdrive.

You may also find a few effects builds that I am looking to move on - usually in exchange for other effects/gear/cash. You can always check my ebay account to see what I've got up for grabs.

Have fun, enjoy the blog - Fred Briggs :-)

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Feel free to get in contact with me about anything you see on this blog or with any general questions about guitars, amplifiers and effects, I'll be happy to answer! Just click the button above to email me directly or alternately my email address is fredbriggs2007 [at] googlemail [dot] com

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Tuesday, 27 May 2008

The larger white box is my latest Klown, modeled on the Klon circuit but modified for a fatter OD sound, with split gain and blend pots, altered clipping arrangement and altered the op-amp type.

The smaller silver box with blue and white paint is a "new" circuit I've come up with. By mixing and matching, in traditional booteek fashion, different sections of popular overdrive circuits. This circuit is a mix between the OCD/Voodoo labs OD the Hermida Zendrive and the Clay Jones OD. Sounds great, super dynamic and with internal sockets for altering the clipping diode type and position the combinations you can come up with are immense!

Tuesday, 20 May 2008

Everyone likes originals? Here is the Analogman - KOT (King of Tone) schematic, looks just like a modified Marshall Bluesbreaker pedal to me. But you do get two of these circuits in series when you buy the KOT, which is pretty cool, and the build quality is good. The only problem is waiting time - approx 1.5 years! Here is the great Torchy's project which will allow you to build one half of the KOT, for full KOT build two of these and stick em in the same the box! Thanks again Torch, your a king.

Go wild! Here's the scheme, as you can see it's the standard setup now-a-days of opamp with clipping diodes. Paul C, the designer of the timmy has commented alot on the subject of his pedal over at freestompboxes.org. He still sells the originals directly from himself for around $100 I believe - that is simply the deal of the century when your looking at the bootweek industry! GET ONE FROM HIM NOW! If you fancy trying to build one yourself, here's the scheme!

The Timmy has been cloned the world over due to it's great versitility and tone - the Danelectro Cool Cat Transparent OD 1 was a direct clone and the Lovepedal Amp eleven and OD eleven are both Timmy clones. It's a very nice little circuit and well worth playing with. Here's a nice demo video for you:

And here's another interesting mod - using a feedback arrangement ala the BJF Honeybee and my own Hummingbird to reduce the overall gain and brightness of the unit:

And some interesting options for clipping diodes using a couple of switches. Point A is the - input of the opamp point B is the opamp output:

However if you are going to play with diodes heed this advice from PaulC himself:

"I've stated this above, but if you do play around with other diodes/no diodes you have to adjust the output amp or else you may get nasty rail clipping. As is with the gain on zero you've got 6db of gain on the first stage feeding into 6db of gain on the second stage for a total of 12db. Without diodes (and ignoring rail clipping) that 1st stage swings from a gain of 2 up to about 153 in the Tim (500k pot), and 304 in the Timmy (1M pot). This will totally puke out the output amp.

If you want to leave out the diodes for a clean boost, but keep the tone controls I'd mess with dropping the output amp, and just make it a buffer. Then back down the gain of the 1st stage so you don't get clipping. Now you've got a simple opamp booster with bass/treble controls which is actually the original circuit (what a minute - does that mean it didn't start out as a yats??). If I was going with LED's or true mosfet clippers I'd also switch the output amp to a buffer so it wouldn't clip under the larger signal. Better yet if you've got things on a switch have the switch also change the gain of the output amp when you're switching different diodes. You could remove the gain for the large diodes, and put it back for the small. That would solve the loss of volume you get from the standard diode selectors. You could also have some EQ'ing around the output amp to shape things even more. Have it set up to short out the feedback resistor for a flat buffer when using LED's/boosting, or add a cap across the feedback loop and another in series with the inv input to maybe put in a slight mid bump along with the extra gain when using small threshold diodes. Those caps would be added to the circuit, and one pole of the switch would just short out the loop.

I really wouldn't just pull the diodes if I was wanting it to be just a flat booster. There's better ones with more headroom for that.

Later, PaulC"

And some advice on a possible opamp substitutions from twangquack:

"What was not fruitless was experimentation with op-amp substitutions. Unlike a OCD clone on which I did some further tweaking, it was hard to find an op-amp that was a total failure -- that's how sane and well-behaved this circuit is (but in a good way). After trying about fifteen options, alone and dual-stacked, I found that I really liked the TL072 (socket soldered on top) with a BB OPA2134. This is a combo with a bit of added "oomph" that retains the nice treble qualities without adding somewhat extreme tonal qualities that sometimes happens with certain stacked op-amp combinations. I also liked a RC4559 (alone) but it seemed a bit too dark to me, although it had really nice drive -- sounded pretty cool at higher drive levels. But I think I like this pedal to be spankier and used at lower drive levels (hint of grit, or a bit more than a hint) so the TL072 + OPA2134 works very nicely in this particular build."

And here is a demo video (there are plenty of sound samples on the Hermida website though...);

A full project, presented by the freestompboxes forum member "stratotrasto". What a great project, complete with drilling templates for an enclosure! Here it is. Many thanks Strato!

Now the Fuchs Plush Drive - Well, it's just a Zendrive clone. Here's the evidence:

And the Jetter Gain Stage Red:

Soulsonic traced one out, here's what he found:

And the Schematic of the Gain Stage Red:

And here's what he had to say about it:

"Yes, it's almost an exact clone of the Hermida Zendrive. The differences are minimal if you can even call them differences. Instead of the "Voice" control, the Jetter has the "Hard/Soft" switch which toggles between two static values of the exact same "Voice" circuit. The 100pF cap has been omitted from the feedback loop of the overdrive section. The Tone control is 100K linear, instead of 50K. A reverse polarity protection diode has been added... that's about it. The opamp type is unknown - the numbers have been sanded off it. The MOSFETs have been sanded as well, but my Atlas DCA correctly identified them as N-Channel Enhancement Mode MOSFETs, which means they are likely the usual 2N7000/BS170 type. Two of the diodes are those same kind of little blue glass ones as Kerry described were in the Zendrive, and the other diode is a 1N60 or similar germanium (also like described as being in the Zendrive)."